Re: GtkTreeView drag and drop

[Bill Wilson <billw wt net>]

On Thu, 20 Jun 2002 13:20:44 -0700
Lunatics <lunatics zenlunatics com> wrote:

> I'd like to use the default drag on drop handlers for GtkTreeView with 
> gtk_tree_view_enable_model_drag_dest(). The motion handler draws boxes 
> around nodes in the view but also lines in between nodes. I'd like to 
> set it so that it only draws the boxes and not the lines. In other words 
> I'd like to restrict drop targets to existing nodes and not allow 
> dropping in between nodes. Is this possible and if so, what do I need to do?

Probably getting the draw to do what you want is difficult, but you
can resrict the drop target to nodes/levels you want if you intercept
the row_drop_possible in the destination drag interface (don't know if
this is considered private data?):

static gboolean (*default_row_drop_possible)();

static gboolean
row_drop_possible(GtkTreeDragDest *drag_dest, GtkTreePath *path,
            GtkSelectionData *selection_data)
    {
    gint    *indices, depth;

    indices = gtk_tree_path_get_indices(path);
    depth = gtk_tree_path_get_depth(path);
    if (/* Whatever indices/depth criteria for dissallowing the drop */ )
        {
        return FALSE;
        }
    return (*default_row_drop_possible)(drag_dest, path, selection_data);
    }


and when you create the model, set it up:

    GtkTreeDragDestIface *dest_iface;

    model = create_model();
    dest_iface = GTK_TREE_DRAG_DEST_GET_IFACE(GTK_TREE_DRAG_DEST(model));
    default_row_drop_possible = dest_iface->row_drop_possible;
    dest_iface->row_drop_possible = row_drop_possible;
    treeview = GTK_TREE_VIEW(gtk_tree_view_new_with_model(model));

Bill